jphughan

I've actually gone back and forth on this both entering T2 (3rd vs 4th) and through the carousel (upshift to 4th mid-corner or go to 4th before entering), in both the GT4 and even a bit with the M3 when I had it. I didn't log any data this past weekend, but I feel much faster going through T2 in 3rd. I do indeed have to shift to 4th while moving over toward the right of the track before the bridge (where I'm not sideloaded enough for that to be a concern) and then right back to 3rd before T4. Is going flat in 4th actually faster than modulating 3rd? And in the carousel, my exit speed is ~4 MPH faster when I upshift mid-corner rather than taking the whole thing in 4th. When upshifting mid-corner, I do it at the widest point of my arc through the carousel where I'm trailing throttle anyway to tuck in a bit on the way to the second apex, so it feels ok, although one lap I did mess it up and upset the car enough for ESC to kick in, and I agree that's not a good place for that to happen. I'd definitely go through the whole carousel in 4th in the wet. I'll have to continue experimenting.

Well with the caveat that I haven't delved into left foot braking yet, is there still somewhere that I should actually be braking rather than just trailing off throttle to improve turn-in for the second apex of the carousel? The car feels pretty heavily sideloaded to me all through there, so it feels like applying any brake would bring the rear around, but I'm also still new to the GT4 and even this type of car (mid-engine, Cup 2 tires, aero grip, etc), so I'm definitely open to suggestions. Or is that just yanking my chain??

katmeho

These details make me realize I have no idea what I was doing. I was holding 3rd out of T1 all the way to T6 and just tossing the car to knock off speed. The only way I was making it through there was because of Daves (?) comments on track walk about apex the gantry bridge...

Must. Go. Back.

jphughan

In the M3 I used 3rd through T1 (and T11, 12, and 15) mostly because the 3>2 downshift is a tricky rev match in that car, plus 2nd makes corner exit throttle management a lot harder in those segments, which in the case of T1 seemed a cost with no benefit since I would also short shift to 4th before T2 because the M3's weight, lower overall grip, and understeer tendency compared to the GT4 seemed to prevent me from getting much more by going through there in 3rd. But in the GT4 thanks to the Sport button and its superior setup, I take T1 in 2nd and can power out of there nicely. I could maybe skip the upshift to 4th in the mini-straight before the bridge, but I'd probably be on the limiter, and maybe ShakeNBake on his slicks has a different experience, but I don't know if I'd have the stones to turn into T3 in 3rd at very high revs. I usually breathe off the throttle very slightly to facilitate that turn-in, and attempting that in 3rd at high revs would probably get me more weight transfer than I wanted and induce some undesirable yaw -- plus I figure if I already need some throttle steer based on the speed I'm carrying by turn-in even with the shift to 4th, and given that I don't want to brake prior to T3 turn-in, there's no point staying in 3rd the whole way and consequently arriving at turn-in with even more speed that I won't be able to carry into the corner.

Olcha911

"Well with the caveat that I haven't delved into left foot braking yet, is there still somewhere that I should actually be braking rather than just trailing off throttle to improve turn-in for the second apex of the carousel? The car feels pretty heavily sideloaded to me all through there, so it feels like applying any brake would bring the rear around, but I'm also still new to the GT4 and even this type of car (mid-engine, Cup 2 tires, aero grip, etc), so I'm definitely open to suggestions. Or is that just yanking my chain??"

I think your analysis is correct. While I am no expert, I have driven COTA quite a bit. the last time I raced there was two PCA races ago. I think entering the carousel as hard as you can in 3rd, and then instead of the easing the throttle, short shifting into 4th and then carry speed until easing again for the second apex is what most people do. FYI- my results from two years ago -Keith

jphughan

Oh interesting, if I didn't shift to 4th before the entire carousel, I would shift in that second segment you're talking about, i.e. while easing off throttle before heading for the second apex. Are you suggesting turning in while still in 3rd and then shifting to 4th on the way to the first apex? That hadn't even occurred to me, but thinking about it now, it may be the Goldilocks solution. It would undoubtedly be easier and safer to execute a shift in that segment, there's not much speed to be gained anyway between the first apex and the spot where you ease throttle to tuck in before adding power on the way to the second apex, and this strategy might still give me the extra speed I'm noticing from turning in while still in 3rd. If I'm understanding you correctly, that sounds like a cool idea. Thanks!

Olcha911

Yes- because you're not loading up that much G's yes until you are well into the carousel.

MM3.9GT3

On R compound tires (MPSC2, Trofeo etc.) can a GT4 break 2:25? What about a 991 GT3 on the same tires? On equally skilled hands, how much slower is the GT4 vs. GT3?

Thanks for the great videos.

ShakeNBake

The GT4 CS guys were in the 2:23-25 range in the front, and 2:30 in the back - on Pirelli DH tires, at the Pirelli Trophy Cup a couple weeks ago. A 25 on Cup2s or Trofeo R would be pretty exceptional. Mind you the Trophy cup is not a Pro series, so these are fast drivers, but not Porsche Factory guys, etc. I think an amazing time on Cup2s would be 28. Fastest 991 GT3 time I know of on Cup2s, though I don't have the data to know how, was in the 24s. Net is I think the GT3 is 3-4 seconds faster in mortal hands. Not sure about gods.

MM3.9GT3

Thanks. This is exactly the information I was looking for. I am trying to decide between a GT4, and a 991 GT3.

ShakeNBake

If you care mostly about lap times, then a Viper ACR, M4 GTS, GTR are all/will be faster around COTA. Edit - than a GT4 or a GT3.

MM3.9GT3

It will primarily be used as a track car. The M4 GTS, or a M3/M4 with the competition package is interesting.

Uncle Jed

I'm living vicariously through Shake N Bake's videos while I wait for my GT4. Keep 'm coming!

Uncle Jed

jphughan

Having come from an M3 that I absolutely loved to a GT4, if you want a primarily track car, don't get an M3/4, except maybe an E46/E36 with the intent of modifying it fairly significantly. M3s (and now the M4) are I think still the reigning champ when you want to have ONE car that can hold up to track usage and still remain absolutely usable on a daily basis, and I think they balance performance, comfort/convenience, tech gadgetry, practicality, styling, price, and overall fun better than any other car out there, with the possible exception of a Golf R if you'll trade some track chops for extra practicality and lower cost. But a GT4 or GT3 (at least a 991) can be used as a DD if your needs there are fairly minimal, and they'll do much better on the track. And that's without even looking at Vettes, Vipers, GTRs, etc. as mentioned above.

ShakeNBake

I was talking about a M4 GTS, which is going to be a ridiculous badsh1tcrazy car, and my point was that if you are worried about the fastest car, don't get a GT4 or a GT3...there are much faster cars out there.

jphughan

Yes, the GTS is definitely going to be a different animal, although it looks like it's going to be really hard to get (you have to submit an application for an allocation, 918 Spyder style) and its $150K price puts it right up with the GT3, and I don't know if that will be justified on the basis of lap times. I sure hope so, because if it's not, something as track-focused as the GTS can't say, "Yeah we don't have GT3 lap times, but at least we're more usable on the road." I wrote that post above mostly because the M3/4 with competition package was mentioned, and while the F8x generation competition package definitely looks to be fairly significant, I don't think it will change the equation enough to nullify what I said. The cars simply have different design goals.